import numpy as np
import matplotlib.pyplot as plt

#对数函数
x = np.linspace(0.1,10,99,endpoint = False)
y1 = np.log2(x)
y2 = np.log(x)
y3 = np.log10(x)

plt.plot(x,y1,'red',x,y2,'yellow',x,y3,'blue')

plt.show()